It is becoming more and more common to have wireless communication networks in relation to industrial processes, such as pulp and paper processes, manufacturing processes and oil and gas production processes.
These wireless communication networks are normally wireless sensor networks in that they are used for sensing various properties of the process, such as pressure and temperature and then reporting these wirelessly to monitoring equipment.
One known type of wireless sensor network standard is Wireless Hart.
It is of interest to also use such wireless communication networks for control of the process. This means that properties are sensed and based on the sensed properties a control activity is determined and performed.
This control often has to be performed in real-time, which means that a control activity has to be based on a number of simultaneously sensed properties and often also performed fairly fast after the point in time of the sensing. The control thus imposes restrictions on the wireless communication network, communication restrictions, which may be hard to meet.
This problem is briefly mentioned in “Real-Time Scheduling for WirelessHART Networks”, by Abusayeed Saifullah, You Xu, Chenyang Lu, and Yixin Chen in the Technical Report WUCSE-2010-26 from Washington University in St Louis dated May 14, 2010. The document does however not propose any real solution to the problem.
The present invention is directed towards solving the problem of meeting such communication restrictions in wireless communication networks used in a process control system.